Cracks and fingers: dynamics of ductile fracture in an aqueous foam

Stewart, P. S. and Hilgenfeldt, S. (2017) Cracks and fingers: dynamics of ductile fracture in an aqueous foam. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 534, pp. 58-70. (doi: 10.1016/j.colsurfa.2017.03.057)

Abstract

Fracture of a quasi-two-dimensional aqueous foam by injection of air can occur via two distinct mechanisms, termed brittle and ductile, which are analogous to crack modes observed for crystalline atomic solids such as metals. In the present work we focus on the dynamics and morphology of the ductile process, in which no films between bubbles are broken. A network modeling approach allows detailed analysis of the foam morphology from individual bubbles to the shape of the propagating crack. This crack develops similarly to fingering instabilities in Hele–Shaw cells filled with homogeneous fluids. We show that the observed width and shape of the crack are compatible this interpretation, and that the discreteness of the bubble structure provides symmetry perturbations and limiting scales characteristic of anomalous fingering. The model thus bridges the gap between fracture of the solid foam lattice and instability growth of interfaces in a fluid system.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Stewart, Professor Peter
• Authors: Stewart, P. S., and Hilgenfeldt, S.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Mathematics
• Journal Name: Colloids and Surfaces A: Physicochemical and Engineering Aspects
• Publisher: Elsevier
• ISSN: 0927-7757
• ISSN (Online): 1873-4359
• Published Online: 05 April 2017